Fabrication of L1 0-MnAl perpendicularly magnetized thin films for perpendicular magnetic tunnel junctions

Abstract

Structural and magnetic properties of MnAl thin films with different composition, growth temperature, and post-annealing temperature were investigated. The optimum condition for fabrication of L1 0-MnAl perpendicularly magnetized thin film deposited on Cr-buffered MgO single crystal substrate was revealed. The results of x ray diffraction indicated that the MnAl films annealed at proper temperature had a (001)-orientation and L1 0-ordered structure. The L1 0-ordered films were perpendicularly magnetized and had a large perpendicular anisotropy. In addition, low surface roughness was achieved. For the optimized fabrication condition, the saturation magnetization M s of 600 emu/cm 3 and perpendicular magnetic anisotropy K u of 1.0 × 10 7erg/cm 3 was obtained using the Mn 48Al 52 target at deposition temperature of 200°C and post-annealing temperature of 450°C. © 2012 American Institute of Physics.